Multi-limit fault detection circuit and system
By designing a multi-limit fault detection circuit with a combination of parallel control branch and relay in the limit control circuit, the fault limit switch is quickly positioned by changing the state of the relay contact point, the problem of difficulty in positioning the limit switch fault is solved and the detection is improved Efficiency and accuracy avoid the risk of breaking up the wrong lines.
Patent Information
- Application Number
- CN202420549183.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-03-20
AI Technical Summary
In the limit control circuit, it is difficult to quickly locate the limit switch when it fails, which makes manual inspection time-consuming and labor-intensive. Moreover, due to the messy lines, it is easy to remove the wrong lines, which increases the difficulty and risk of fault search.
Design a multi-limit fault detection circuit, through the combination of parallel control branch and relay, the fault limit switch is quickly positioned by changing the contact state of the relay, avoiding the disassembly of the wrong line, and ensuring the indication unit of the fault limit switch A conduction loop is formed with the power supply to display the fault location.
It realizes rapid positioning of fault limit switches, saves time and effort, avoids the situation of dismantling wrong lines, improves the efficiency and accuracy of fault detection, and ensures the stable operation of the equipment.
Smart Images
Figure CN222319086U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of limit detection, and in particular relates to a multi-limit fault detection circuit and system. Background Art
[0002] With the development of industrial automation, the importance of limit control circuits has gradually become prominent. It can accurately control the movement position of the equipment, ensure that the equipment operates within the preset position range, avoid overshoot or undershoot of the equipment, and improve the stability and reliability of the equipment. At the same time, the limit control circuit can also improve production efficiency, reduce manual operation costs, and avoid the occurrence of safety accidents.
[0003] During the packaging and bundling process of the strapping machine, a limit circuit is required for automatic control to improve production efficiency, ensure the stability and reliability of the machine, avoid excessive bundling, etc. During the use of the limit control circuit, limit switch failure is prone to occur.
[0004] See also Figure 1 As shown, the traditional strapping machine system uses multiple limit switches in series and connects to the PLC system end through a signal line. When one of the limit switches fails, when the strapping machine triggers each limit switch, the faulty limit switch will not be triggered, and the series lines of each limit switch will be disconnected, causing the PLC system end to be unable to receive the signal generated by the limit switch being triggered, that is, when one limit switch fails, the other limit switches cannot be used normally. In addition, when a limit switch fails, it is not certain which limit switch is faulty, and manual inspection is required one by one, which is time-consuming and labor-intensive. In addition, since the power lines of each limit switch and the power lines and the signal lines are often parallel and the line connections are messy, it will further increase the obstacles to finding the faulty limit switch, and the messy lines are also easy to remove the wrong line. Utility Model Content
[0005] The utility model aims to provide a multi-limit fault detection circuit and system, which can quickly locate the faulty limit switch, save time and labor, and help avoid the situation of wrong line removal.
[0006] In order to achieve the above object, the utility model provides a multi-limit fault detection circuit, comprising:
[0007] A control module, wherein the control module comprises a plurality of parallel control branches, each of which is provided with a limit switch and a sensing part of a relay, and a signal output end of the limit switch is used to output a signal to the sensing part of the relay;
[0008] The execution part of each relay is sequentially connected in series between the power supply and the system end, and the execution part includes a first contact and a second contact, wherein when the first contact of each relay is in a closed state, the line between the power supply and the system end is turned on, and the second contact of each relay is connected to the power supply and an indication unit;
[0009] Under normal conditions, the second contact of each of the relays is in a closed state, and the line between the power supply and the system end is disconnected;
[0010] When the limit switches are triggered simultaneously, according to the change of the output signal of the corresponding limit switch, the second contact of each relay is switched to an open state, and the first contact of each relay is switched to a closed state;
[0011] When any of the limit switches fails and the other limit switches are triggered simultaneously, the second contact of the relay corresponding to the failed limit switch is in a closed state, the first contact is in an open state, and the indication unit corresponding to the failed limit switch and the power supply form a conducting circuit.
[0012] Optionally, the limit switch is a normally open limit switch, and a short-circuit branch is connected in parallel to the limit switch. A switching switch is provided on the short-circuit branch. Under normal circumstances, the switching switch is in an open state. When the limit switch fails, the corresponding switching switch is changed to a closed state, and the short-circuit branch outputs a signal to the induction part of the relay corresponding to the faulty limit switch, so that the second contact of the relay is switched to an open state and the first contact is switched to a closed state.
[0013] Optionally, a fuse is connected in series between the limit switch and the induction part of the relay, and the short-circuit branch is connected in parallel with the series branch of the limit switch and the fuse.
[0014] Optionally, a fuse is connected in series between the limit switch and the inductive part of the relay.
[0015] Optionally, the limit switch is a normally open limit switch or a normally closed limit switch.
[0016] Optionally, the limit switch is a PNP limit switch or an NPN limit switch.
[0017] Optionally, the relay is an electromagnetic relay, and the induction part of the relay is a coil.
[0018] Optionally, the negative pole of the power source is connected to a common line, a plurality of connection nodes are provided along the common line, and each of the indicating units is respectively connected between the corresponding connection node and the second contact of the relay.
[0019] Optionally, the indicating unit is an indicator light.
[0020] In order to achieve the above-mentioned purpose, the utility model also provides a multi-limit fault detection system, including a device, a system end and the multi-limit fault detection circuit as described above, wherein each limit switch of the multi-limit fault detection circuit is used to perform position detection on the device in operation and is triggered simultaneously by the device, and when each limit switch is triggered simultaneously, a conductive circuit is formed between the power supply and the system end by connecting the closed first contacts.
[0021] In the utility model, when any limit switch fails, the signal output end of the limit switch has no signal output to the induction part of the corresponding relay, just like when it is not triggered, so that the second contact of the relay is in a closed state and the first contact is in a disconnected state. Since the first contacts of the corresponding relays of other limit switches will be in a closed state and the second contacts will be in a disconnected state when they are triggered, the indication unit and the power supply corresponding to the failed limit switch will form a conduction loop, and no conduction loop will be formed between other indication units and the power supply, so that the indication unit located in the conduction loop will issue an indication, which is convenient for quickly locating the failed limit switch, saving time and effort, and helping to avoid the situation of removing the wrong wires. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 Schematic diagram of the limit module used in traditional strapping machines.
[0023] Figure 2 This is a schematic diagram of the multi-limit fault detection circuit in a normal state according to an embodiment of the utility model.
[0024] Figure 3 This is a schematic diagram of the case where each limit switch of the multi-limit fault detection circuit of the embodiment of the utility model is triggered simultaneously.
[0025] Figure 4 This is a schematic diagram of a case where a certain limit switch of the multi-limit fault detection circuit of an embodiment of the utility model fails and other limit switches are triggered simultaneously.
[0026] Figure 5 This is a schematic diagram of a switching switch connected in parallel with a fault limit switch of a multi-limit fault detection circuit according to an embodiment of the utility model when the switching switch is closed and other limit switches are triggered simultaneously. DETAILED DESCRIPTION
[0027] In order to explain the technical content, structural features and effects achieved by the present invention in detail, the following is a detailed description in conjunction with the implementation modes and the accompanying drawings.
[0028] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.
[0029] See also Figures 2 to 4 The embodiment of the utility model discloses a multi-limit detection control circuit, including a control module, the control module including a plurality of parallel control branches 1, each control branch 1 is provided with a limit switch 10 and a sensing part 21 of a relay 20, and the signal output end of the limit switch 10 is used to output a signal to the sensing part 21 of the relay 20. The execution part of each relay 20 is sequentially connected in series between the first power supply and the system end, and the execution part includes a first contact 22 and a second contact 23, wherein when the first contact 22 of each relay 20 is in a closed state, the line between the first power supply and the system end is turned on, and the second contact 23 of each relay 20 is connected to the first power supply. The indicating unit 30 is connected. Under normal conditions (i.e., when the limit switch 10 is normal and not triggered), the second contact 23 of each relay 20 is in a closed state, and the line between the first power supply and the system end is disconnected. When each limit switch 10 is triggered at the same time, according to the change of the output signal of the corresponding limit switch 10, the second contact 23 of each relay 20 is switched to an open state, and the first contact 22 of each relay 20 is switched to a closed state. When any of the limit switches 10 fails and the other limit switches 10 are triggered simultaneously, the second contact 23 of the relay 20 corresponding to the failed limit switch 10 is in a closed state, the first contact 22 is in an open state, and the indicating unit 30 corresponding to the failed limit switch 10 and the first power supply form a conducting loop. Specifically, the system end is a PLC system end, but is not limited thereto.
[0030] In the utility model, when any limit switch 10 fails, the signal output end of the limit switch 10 does not output a signal to the induction part 21 of the corresponding relay 20, just like when it is not triggered, so that the second contact 23 of the relay 20 is in a closed state and the first contact 22 is in a disconnected state. Since the first contacts 22 of the corresponding relays 20 of other limit switches 10 will be in a closed state and the second contacts 23 will be in a disconnected state when they are triggered, the indication unit 30 corresponding to the failed limit switch 10 and the first power supply will form a conduction loop, and no conduction loop will be formed between the other indication units 30 and the first power supply, so that the indication unit 30 located in the conduction loop will issue an indication, which is convenient for quickly locating the failed limit switch 10, saving time and effort, and helping to avoid the situation of removing the wrong wires.
[0031] Please further combine Figure 5 In some embodiments, the limit switch 10 is a normally open limit switch, and the limit switch 10 is connected in parallel with a short-circuit branch 40, and a switch 41 is provided on the short-circuit branch 40. Under normal conditions, the switch 41 is in an open state. When the limit switch 10 fails, the corresponding switch 41 is changed to a closed state, and the short-circuit branch 40 outputs a signal to the inductive part 21 of the relay 20 corresponding to the failed limit switch 10, so that the second contact 23 of the relay 20 is switched to an open state, and the first contact 22 is switched to a closed state. Since the first contact 22 will remain in a closed state, it will not affect the use of other limit switches 10. During the period of repairing or replacing the failed limit switch 10, other limit switches 10 can be used to perform the limit detection function, so that the device can still operate normally, which effectively reduces the impact of the limit switch 10 failure on the normal operation of the device. Of course, the limit switch 10 is not limited to the need to connect the short-circuit branch 40 in parallel.
[0032] Specifically, the switch 41 is a two-position knob, but is not limited thereto.
[0033] Specifically, a fuse 50 is connected in series between the limit switch 10 and the inductive part 21 of the relay 20, and the short-circuit branch 40 is connected in parallel with the series branch of the limit switch 10 and the fuse 50. Through the setting of the fuse 50, when the current exceeds a certain value, the fuse 50 will melt, cut off the circuit, and prevent the circuit from overloading. Of course, the fuse 50 is not necessarily set.
[0034] In some embodiments, a fuse 50 is connected in series between the limit switch 10 and the inductive part 21 of the relay 20. By setting the fuse 50, when the current exceeds a certain value, the fuse 50 will melt, cut off the circuit, and prevent the circuit from overloading. Of course, the fuse 50 is not necessarily set.
[0035] In some embodiments, the limit switch 10 is a normally open limit switch or a normally closed limit switch. If the limit switch 10 is a normally open limit switch, under normal conditions, the limit switch 10 does not provide a signal to the sensing part 21 of the corresponding relay 20. At this time, the second contact 23 of the relay 20 is in a closed state, and the first contact 22 is in an open state. When the limit switch 10 is triggered, it will output a level signal to the sensing part 21 of the corresponding relay 20, so that the second contact 23 of the relay 20 becomes an open state, and the first contact 22 becomes a closed state. When the limit switch 10 fails, the limit switch 10 also does not provide a signal to the sensing part 21 of the corresponding relay 20. At this time, the second contact 23 of the relay 20 is in a closed state, and the first contact 22 is in an open state. If the limit switch 10 is a normally closed limit switch, under normal conditions, the limit switch 10 will output a level signal to the sensing part 21 of the corresponding relay 20. At this time, the second contact 23 of the relay 20 is in a closed state, and the first contact 22 is in an open state. When the limit switch 10 is triggered, no signal is provided to the sensing part 21 of the corresponding relay 20, so that the second contact 23 of the relay 20 becomes an open state, and the first contact 22 becomes a closed state. When the limit switch 10 fails (it cannot be triggered but the output level signal can be maintained when not triggered), the limit switch 10 provides a level signal to the sensing part 21 of the corresponding relay 20. At this time, the second contact 23 of the relay 20 is in a closed state, and the first contact 22 is in an open state.
[0036] Specifically, the limit switch 10 can be a PNP type limit switch or an NPN type limit switch. In the example of the accompanying drawings, the limit switch 10 is a PNP type limit switch, and its two power lines are respectively connected to the positive and negative electrodes of the second power supply. The second power supply here can be the same power supply as the first power supply mentioned above, or they can be different power supplies.
[0037] In some embodiments, the relay 20 is an electromagnetic relay, and the inductive part 21 of the relay 20 is a coil. The armature of the electromagnetic relay 20 is connected to the first contact 22 or the second contact 23 based on the change of the signal received by the coil, thereby making the first contact 22 in a closed state or the second contact 23 in a closed state.
[0038] In some embodiments, the negative electrode of the first power supply is connected to a common line 60, a plurality of connection nodes 61 are provided along the common line 60, and each indicating unit 30 is respectively connected between the corresponding connection node 61 and the second contact 23 of the relay 20. Of course, it is not limited to this, for example, the indicating unit 30 may also be independently connected to the negative electrode of the first power supply, or some indicating units 30 may be connected to the negative electrode of the first power supply through the common line 60, and some indicating units 30 may be independently connected to the negative electrode of the first power supply.
[0039] In some embodiments, the indicating unit 30 is an indicator light. If one limit switch 10 fails, when other limit switches 10 are triggered at the same time, the indicator light corresponding to the failed limit switch 10 will form a conduction loop with the first power supply, and other designated lights will not form a conduction loop with the first power supply, and then the lit indicator light can indicate the failed limit switch 10, so as to achieve rapid positioning.
[0040] To facilitate understanding of the present invention, the following briefly describes the use of the circuit in the example of the accompanying drawings, which should not be considered as limiting the present invention.
[0041] See also Figure 2 Under normal conditions, each limit switch 10 is intact and can work normally. At this time, as a normally open limit switch 10, no signal is output to the coil of the relay 20, the second contact 23 of each relay 20 is in a closed state, the first contact 22 is in an open state, and the line between the first power supply and the system end is disconnected. Except for the first indicator light on the left side of the figure, the other indicator lights are all off because the current cannot flow to the other indicator lights.
[0042] See also Figure 3 When the running equipment is triggered at the same time, each limit switch 10 outputs a level signal to the coil of the relay 20 connected to it, the second contact 23 of each relay 20 is in an open state, and the first contact 22 is in a closed state, so that the line between the first power supply and the system end is conductive, and then the system end can receive the signal and can execute the control of the equipment accordingly.
[0043] See also Figure 4 , when a limit switch 10 fails, for example, the third limit switch 10 from left to right in the figure fails, the third limit switch 10 has no signal output to the coil of the relay 20, and the corresponding second contact 23 of the third relay 20 from left to right in the figure is in a closed state, the first contact 22 is in an open state, and the line between the first power supply and the system end is disconnected. Then when other limit switches 10 are triggered at the same time, the second contact 23 of the corresponding relay 20 is in an open state, and the first contact 22 is in a closed state, but because the first contact 22 of the third relay 20 is in an open state, the line between the first power supply and the system end will not be conductive, and the system end will not receive a signal. However, since the first contacts 22 of the first and second relays 20 from left to right in the figure are in a closed state, the indicator light connected to the second contact 23 of the third relay 20 and the first power supply can form a conductive loop, and then the indicator light can light up, while other indicator lights will not light up.
[0044] See also Figure 5When the third limit switch 10 is confirmed to be faulty, the switch 41 on the short-circuit branch 40 connected in parallel can be changed from the open state in the normal state to the closed state. At this time, the short-circuit branch 40 will output a level signal to the coil of the third relay 20, thereby switching the second contact 23 of the third relay 20 to the open state and the first contact 22 to the closed state. Since the first contact 22 will remain in the closed state, it will not affect the use of other limit switches 10. After the third limit switch 10 resumes function (replacement or repair), the corresponding switch 41 can be disconnected, and all limit switches 10 are restored to perform limit detection of the equipment.
[0045] The utility model also discloses a multi-limit fault detection system, including equipment, a system end and the multi-limit fault detection circuit as described above, wherein each limit switch 10 of the multi-limit fault detection circuit is used to perform position detection on the running equipment and is triggered by the equipment at the same time, and when each limit switch 10 is triggered at the same time, a conducting circuit is formed between the first power supply and the system end by connecting the closed first contacts 22.
[0046] Specifically, the device may be a strapping machine or other devices.
[0047] The above embodiments are only preferred implementation modes of the present invention, and the implementation modes of the present invention are not limited by the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principle of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.
Claims
1. A multi-limit fault detection circuit, characterized in that: include: A control module, wherein the control module comprises a plurality of parallel control branches, each of which is provided with a limit switch and a sensing part of a relay, and a signal output end of the limit switch is used to output a signal to the sensing part of the relay; The execution part of each relay is sequentially connected in series between the power supply and the system end, and the execution part includes a first contact and a second contact, wherein when the first contact of each relay is in a closed state, the line between the power supply and the system end is turned on, and the second contact of each relay is connected to the power supply and an indication unit; Under normal conditions, the second contact of each of the relays is in a closed state, and the line between the power supply and the system end is disconnected; When the limit switches are triggered simultaneously, according to the change of the output signal of the corresponding limit switch, the second contact of each relay is switched to an open state, and the first contact of each relay is switched to a closed state; When any of the limit switches fails and the other limit switches are triggered simultaneously, the second contact of the relay corresponding to the failed limit switch is in a closed state, the first contact is in an open state, and the indication unit corresponding to the failed limit switch and the power supply form a conducting circuit.
2. The multi-limit fault detection circuit according to claim 1, characterized in that: The limit switch is a normally open limit switch, and a short-circuit branch is connected in parallel to the limit switch. A switching switch is provided on the short-circuit branch. Under normal circumstances, the switching switch is in an open state. When the limit switch fails, the corresponding switching switch is changed to a closed state, and the short-circuit branch outputs a signal to the induction part of the relay corresponding to the failed limit switch, so that the second contact of the relay is switched to an open state and the first contact is switched to a closed state.
3. The multi-limit fault detection circuit according to claim 2, characterized in that: A fuse is connected in series between the limit switch and the inductive part of the relay, and the short-circuit branch is connected in parallel with the series branch of the limit switch and the fuse.
4. The multi-limit fault detection circuit according to claim 1, characterized in that: A fuse is connected in series between the limit switch and the inductive part of the relay.
5. The multi-limit fault detection circuit according to claim 1, characterized in that: The limit switch is a normally open limit switch or a normally closed limit switch.
6. The multi-limit fault detection circuit according to claim 5, characterized in that: The limit switch is a PNP limit switch or an NPN limit switch.
7. The multi-limit fault detection circuit according to claim 1, characterized in that: The relay is an electromagnetic relay, and the induction part of the relay is a coil.
8. The multi-limit fault detection circuit according to claim 1, characterized in that: The negative pole of the power source is connected to a common line, a plurality of connection nodes are arranged along the common line, and each of the indicating units is respectively connected between the corresponding connection node and the second contact of the relay.
9. The multi-limit fault detection circuit according to claim 1, characterized in that: The indicating unit is an indicator light.
10. A multi-limit fault detection system, characterized in that: It comprises a device, a system end and a multi-limit fault detection circuit as described in any one of claims 1 to 9, wherein each limit switch of the multi-limit fault detection circuit is used to detect the position of the device in operation and is triggered simultaneously by the device, and when each limit switch is triggered simultaneously, a conducting circuit is formed between the power supply and the system end by connecting each of the closed first contacts.